In a conventional technology, there has been provided an aseptic filling method as an inline system for forming an aseptic package by, while conveying a preform made of PET (polyethyleneterephtalate), performing a sterilization treatment by blasting a sterilizing agent gas such as hydrogen peroxide or like to the preform, molding the preform into a bottle by a blow-molding machine, filling the bottle with drink, and then capping the bottle (for example, refer to Patent Document 1)
Furthermore, there have been also provided a method in which evaporated sterilizing agent is adhered to a preform, and remaining sterilizing agent is exhausted by flame of a burner (for example, refer to Patent Document 2), and a method in which steam of a sterilizing agent is sprayed to a preform and the preform is heated and then blow-molded (for example, refer to Patent Document 3).
Furthermore, there has been also provided a method of sterilizing a preform without using any sterilizing agent. In such method, water steam is blasted into a preform to heat the preform to a temperature more than glass-transition point and maintain that temperature for a predetermined time for sterilizing the interior of the preform, and immediately thereafter, air is blasted into the preform to remove steam drain from the preform (for example, refer to Patent Document 4).